Re: [vpp-dev] DNS Resolution over VCL
Hi Florin, Thanks for the feedback. I built a very basic application to trigger a TCP request, with gethostbyname() to resolve the hostname, using the VCL library directly. This worked as expected. Just to verify, I ran this also with LD_PRELOAD and I did see the gethostbyname() function stopped working. So it does look like that LD_PRELOAD is having an impact. Anyway, the good news is that VCL is very easy to work. Thanks again for your input. Anthony -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#22116): https://lists.fd.io/g/vpp-dev/message/22116 Mute This Topic: https://lists.fd.io/mt/94581374/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] DNS Resolution over VCL
Hi Florin, Thank you for the reply, much appreciated. I assume that gethostbyname() uses something under the hood that LDP does intercept, otherwise it would continue to use the Linux implementation to resolve hostnames. From what I can see, right now LDP renders gethostbyname() unusable in the application. Are you aware of this behaviour? If so, is there any workaround when using VCL or is it better to just use another mechanism to interface with VPP? I don't have the scope to look at this now, but I will likely need this functionality in the future so would be interested in implementing it when the time comes. I know that you are mainly focused on server side at the moment so this probably isn't much of an issue. I'm getting asked more on the client side these days so it is of interest to me. Thanks again, Anthony -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#22101): https://lists.fd.io/g/vpp-dev/message/22101 Mute This Topic: https://lists.fd.io/mt/94581374/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] DNS Resolution over VCL
Hi all, I still haven't had any luck getting this working. Any ideas? Thanks in advance! Anthony -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#22089): https://lists.fd.io/g/vpp-dev/message/22089 Mute This Topic: https://lists.fd.io/mt/94581374/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
[vpp-dev] DNS Resolution over VCL
Hi all, I have a question regarding DNS lookup from an application using VCL. I'm working with an application that resolves hostnames to IP addresses using the gethostbyname() function. The applications interfaces to the Linux network stack using the epoll API and so seemed like a good candidate for using VCL with LD_PRELOAD. I'm well aware that this may not work but it's worth trying before looking at modifying the interface within the application. The problem I have is that, when using the gethostbyname() function to resolve hostnames, there is no network traffic seen in the VPP network interface. Just to simplify the issue away from the application, the wget tool uses the same function to resolve hostnames. I can confirm that using wget with VCL does work when using an IP address in the URL. However, when passing the hostname in the URL an error occurs failing to resolve the hostname. Again, no packets are seen in VPP when this occurs. I have seen in [1] that the "Caching DNS name resolver" plugin has the ability to "override gethostbyname() in an LD_PRELOAD library" but I don't see any reference on how to override this. Is this the step that I am missing? Just to note, I do have DNS enabled in VPP and have a nameserver configured as 8.8.8.8. I can also cache DNS entries if I add them manually, but this has no impact on the application as there are no packets seen in VPP. Please let me know if any further information would be useful. Thanks, Anthony [1] https://s3-docs.fd.io/vpp/22.06/aboutvpp/featurelist.html -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#22073): https://lists.fd.io/g/vpp-dev/message/22073 Mute This Topic: https://lists.fd.io/mt/94581374/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] TCP Stack Performance Benchmark
Hi Florin, Thank you for the reply. I have seen with Netperf that actually there is TCP traffic going back and forth, a connection is established and then the client side crashes. I'll try to dig deeper to see what might be causing that. All I see on the server side is a received invalid connection message. I don't need to have both server and client using VPP, but I am focused on the client performance. It's a good suggestion, I may try netperf server side outside of VPP to see what that produces (and the other way around). I assume wrk doesn't work with VCL? I'm getting more involved in VPP these days and so I may look to extend existing apps, depending on if it's required. Either way, I'll report back any findings here in case it helps someone else. Thanks again for the response. Anthony -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#21805): https://lists.fd.io/g/vpp-dev/message/21805 Mute This Topic: https://lists.fd.io/mt/93077102/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
[vpp-dev] TCP Stack Performance Benchmark
Hi all, I am currently trying to compare TCP performance between the host TCP vs VPP TCP stack. Mainly I am focused on latency but am struggling to find tools to make the comparison. I have tried looking at iPerf as this has been used with VPP through VCL but this only provides UDP latency numbers. Has anyone attempted to use Netperf using VCL? I have tried but it seg faults but maybe there are steps I can take to enable this? I have also looked at T-Rex although I haven't found a way to generate the test scenarios that I require. Stateful mode does provide tools for TCP testing and benchmarking but T-Rex emulates the TCP stack in this scenario. Any feedback here would be appreciated. Thanks, Anthony -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#21801): https://lists.fd.io/g/vpp-dev/message/21801 Mute This Topic: https://lists.fd.io/mt/93077102/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/leave/1480452/21656/631435203/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
